Vishay Siliconix 3N164

Overview

3N164 from Siliconix is a P-channel enhancement-mode MOSFET designed for ultra-low-leakage analog switching and high-impedance preamplifier applications. It features –30 V drain-source breakdown voltage, –2 to –5 V gate threshold voltage, 300 Ω maximum on-resistance at –20 V gate drive, –3 mA minimum on-state drain current, and 0.7 pF reverse transfer capacitance. It operates in smoke detectors and electrometers where minimal input leakage (<0.02 pA typ.) and high off-isolation are critical.

For engineers reviewing the 3N164 datasheet, 3N164 pinout, 3N164 application, or 3N164 equivalent, key selection criteria include guaranteed low Crss for fast switching, hermetic TO-206AF packaging for reliability in harsh environments, and verified VGS(th) range for predictable turn-on behavior in high-impedance bias networks.

Technical Context

The 3N164 is a lateral P-channel MOSFET with normally-off operation, requiring negative gate voltage relative to source to conduct. Its ultra-low IGSS (<–1 pA at –30 V, 25°C) and high V(BR)GSS (125 V) support precision DC-coupled signal paths without gate leakage-induced drift.

It exhibits temperature-stable switching times (td(on)/td(off) independent of junction temperature), low Crss (0.7 pF), and low Ciss (3.5 pF), enabling use in high-speed analog switches and electrometer front-ends where parasitic capacitance must be minimized to preserve bandwidth and charge integrity.

Key Specifications

Pinout & Package

3N164 is housed in a hermetic TO-206AF (TO-72) metal-can package with axial leads, qualified for military processing per MIL-STD-19500. The package provides high reliability, low moisture ingress, and stable electrical performance across –55°C to +150°C operating junction temperature.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar P-channel MOSFET analog switching applications.

Compared with 3N163 and 2N7000, the 3N164 offers optimized trade-offs for –30 V systems requiring ultra-low leakage and hermetic reliability-neither alternative matches its combination of sub-pA gate leakage, TO-206AF packaging, and P-channel enhancement-mode characteristics in a single device.

Availability

3N164 is available at Aetrix Electronics and suitable for smoke detectors, electrometers, analog switching, and digital switching applications requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for 3N164 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Siliconix, acquired by Vishay in 1998, specialized in high-performance discrete semiconductors including MOSFETs, diodes, and optoelectronics for precision analog and power control applications.

The 3N164 belongs to Siliconix's legacy lateral P-channel MOSFET product line, engineered specifically for ultra-high-impedance, low-leakage analog signal conditioning and switching in safety-critical and scientific instrumentation.

FAQ

What is the maximum drain-source voltage rating for the 3N164?

The 3N164 has a minimum drain-source breakdown voltage V(BR)DSS of –30 V at ID = –10 µA. This rating ensures reliable blocking capability up to –30 V under normal operating conditions and is validated per Siliconix P-37404 Rev. D specifications. Exceeding this voltage risks avalanche conduction and potential device failure. The 3N164 must not be used in circuits where transient or steady-state drain-source voltages exceed –30 V without external clamping.

Does the 3N164 require a negative gate drive voltage to operate?

Yes, the 3N164 is a P-channel enhancement-mode MOSFET and requires a gate-source voltage (VGS) more negative than its threshold range (–2 to –5 V) to conduct. At VGS = 0 V, it remains in the off state. For full enhancement, VGS ≤ –10 V is recommended to achieve the specified ID(on) of –3 mA. The 3N164's normally-off behavior simplifies bias design in high-impedance applications like smoke detector ion chambers.

What is the gate leakage current specification for the 3N164?

The 3N164 specifies gate-body leakage IGSS < –1 pA at VGS = –30 V and TA = 25°C, with a typical value of 0.02 pA. This ultra-low leakage is critical for electrometer and ion-current measurement applications where even femtoampere-level errors degrade accuracy. The 3N164 maintains this performance across its –55°C to +150°C operating junction temperature range, as confirmed in the Siliconix P-37404 datasheet.

Is the 3N164 available in surface-mount packaging?

No, the 3N164 is exclusively offered in the through-hole hermetic TO-206AF (TO-72) metal-can package. No surface-mount variant was released by Siliconix, and no authorized second-source SMT version exists. Designers requiring surface-mount compatibility must select alternative P-channel MOSFETs with comparable leakage and breakdown specs, but those will not be form-, fit-, or function-equivalent to the 3N164.

Can the 3N164 be used as a direct replacement for the 3N163?

The 3N164 is not a direct replacement for the 3N163 due to differences in key parameters: V(BR)DSS (–30 V vs. –40 V), rDS(on) (300 Ω vs. 250 Ω), and ID(on) (–3 mA vs. –5 mA). While both share the same TO-206AF package and pinout, substituting the 3N164 in a 3N163-designed circuit may result in insufficient voltage headroom or higher on-state loss. System validation is required before interchange, and the 3N164 should only replace the 3N163 where –30 V rating and 300 Ω rDS(on) are acceptable.